JPH10170970A - Shake correcting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shake correcting device capable of restraining an offset component outputted after being multiplied by gain at the final stage of a processing circuit to be small without offset adjustment when a vibration detection signal is processed by the processing circuit and quickly converging output voltage to an amplification reference voltage before the output voltage is saturated. SOLUTION: The output voltage from an angular velocity sensor 1 is inputted in a CPU2 through a low-pass filter circuit 40 and an addition amplifier circuit 80. When the output voltage from the circuit 80 exceeds a dynamic range, a PWM control part 2b generates and operation signal SSW, so that the switch 91 of a DC voltage output circuit 90 is operated to be on and off. Based on the DC voltage generated by the circuit 90 and the output voltage from the sensor 1, the output voltage from the sensor 1 is quickly converged to be near to reference voltage Vref by the circuit 80.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects vibration caused by camera shake in a photographing device such as a camera or a video camera,
The present invention relates to a shake correction device for correcting shake.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open Publication No.
A blur correction device as disclosed in Japanese Patent No. 17 is known. This blur correction device detects a blur generated in a camera or a video by a sensor such as an angular velocity sensor, and moves the blur correction lens in a direction opposite to a direction of the blur detected by the sensor to correct the blur.

[0003] A conventional blur correction device will be described below with reference to FIG. FIG. 5 is a block diagram of a conventional blur correction device. The camera body 101 includes a battery 10 that supplies power to the camera body 101 and the lens barrel 102.
3, the camera body side DC / DC converter 104,
Camera body side CP that performs the main control of the camera body side
U105, a main switch 112 for turning on the power switch of the camera, a half-press switch 111 for turning on the first stroke (half-pressed state) of the release button, and a full-on switch for turning on the second stroke (fully pressed state) of the release button. A push switch 110, an operation switch 113, a power supply control switch 130 which is a semiconductor switch, and the like are provided.

The lens barrel 102 includes a lens barrel side CPU 119 for performing main control on the lens barrel side, a lens barrel side DC / DC converter 120, and a 2-bit setting switch for selecting a blur correction control mode. 131,13
A first lens group 1; a shake detector 113, 114 for detecting shake and outputting an output signal corresponding to the shake amount;
25, a second lens group 126, a third lens group (hereinafter, referred to as a blur correction lens) 127 driven in a direction perpendicular or substantially perpendicular to the optical axis direction to correct blur, an aperture blade 128, And motors 123 and 124 for driving the blur correction lens 127, and control circuits 121 and 122 for controlling the driving of the motors 123 and 124, respectively. The conventional shake correction apparatus converts the blur of an image plane formed on a plane into, for example, two X-axis and Y-axis orthogonal to each other.
The blur correction mechanism is driven along each axial direction so as to be decomposed into axial components and cancel the direction of the blur. For this reason, two motors 123 and 124 serving as driving sources are required for two axes to drive the shake correction lens 127, so that the shake detection units 113 and 114 and the motor 12
3 and 124 and the control circuits 121 and 122 are also 2
Each is provided. In the following, the shake detection unit 1
13 will be described.

FIG. 6 is a block diagram showing an example of a shake detection circuit in a conventional shake correction device. As shown in FIG. 6, the shake detecting unit 113 shown in FIG. 5 includes an angular velocity sensor (gyro) 201 and a low-pass filter (hereinafter, referred to as an LPF) 20 connected to the angular velocity sensor 201.
2, a high-pass filter (hereinafter referred to as HPF) 203 connected to the LPF 202, an amplifier (AMP) 204 connected to the HPF 203, and an AMP 20
4 is provided with a shake detection circuit including an A / D converter 205 connected to the A / D converter 4.

The angular velocity sensor 201 is a sensor that detects a blurring state as an angular velocity and outputs an output signal based on the angular velocity.
Is being entered.

The LPF 202 is a filter for cutting a high frequency component from the output signal of the angular velocity sensor 201. The signal from which the high frequency component has been cut is output to the HP of the next stage.
Input to F203.

The HPF 203 is a filter that cuts low frequency components from the signal whose high frequency components have been cut by the LPF 202, and the signal whose low frequency components have been cut is input to the amplifier 204 in the next stage. .

The amplifier 204 amplifies the signal from which the low frequency components have been cut by the HPF 203, and inputs the amplified signal to the A / D converter 205 in the next stage.

The A / D converter 205 is provided with an HPF 203
Converts the analog signal from which the low frequency components have been cut into a digital signal and outputs the digital signal. Since the above-described series of analog signal processing circuits amplify signals in the blur frequency range, the frequency range of the signal to be processed is from several Hz to several tens Hz.

Since the analog-processed data has the dimension of angular velocity, when driving the blur correction lens 127 based on this data, the angular velocity reference value (detection device output reference value) ω0 (hereinafter, referred to as the reference value). Omega Zero) must be calculated. By calculating this omega zero, it is possible to reflect in the correction operation that the state is different from the blurred state when panning is performed at a constant speed. The blur correction lens 127 is driven by a correction amount proportional to the difference between the omega zero and the processing data of the detected angular velocity, and the omega zero is ω0 = (1 / T)
It is calculated by the formula of Σω (t). This is obtained by averaging the sum of the angular velocities ω (t) at each time from time 0 to time T over time T. Ideally, the angular velocity data used in this calculation formula is data detected when it is determined that the output of the angular velocity sensor 201 is stable and the state of the camera is not a blurred state. The longer the averaging time (detection time) T, the better the data stability.

As shown in FIG. 5, the camera body 101 and the lens barrel 102 are provided with electrical contacts 115, 116, 117 and 118 for electrically connecting them. The electric contact 115 is a contact for supplying power from the battery 103 to the lens barrel 102 via the power supply control switch 130. The electrical contact 116 outputs the output of the camera body side DC / DC converter 104 to the lens barrel 1.
This is a contact for supplying power to the 02 side. Electric contact 117
Are the camera body side CPU 105 and the lens barrel side CPU
This is a contact point for performing communication with the communication terminal 119. The electric contact 118 is a contact for connecting a ground (GND) line connected to the cathode terminal of the battery 103.

Next, the operation of the conventional blur correction device will be described. When the main switch 112 is turned on and the half-press switch 111 is turned on, the camera body CPU
An “L” level signal is input to the terminal 105.
When the full-press switch 110 is turned on, an “L” level signal is input to the terminal of the camera body side CPU 105. The camera body side CPU 105 controls the activation of the camera body side DC / DC converter 104 by the ON operation of the half-press switch 111, and
Power is supplied to the lens barrel side CPU 119 through the CPU 16.

The lens barrel side CPU 119 transmits a power supply request signal to the camera body side CPU 10 through an electric contact 117.
5 is output. The camera body side CPU 105 turns on the power supply control switch 130, and the battery 103 connects the lens barrel side DC / DC converter 120 to the electric contact 115.
Powered via. Also, the lens barrel side CPU 119
Is supplied to the lens barrel side D
Activate the C / DC converter 120 and set the lens barrel DC
The / DC converter 120 supplies power to the control circuits 121 and 122 and the motors 123 and 124.

When the setting switch 132 is turned on, the D1 terminal of the lens barrel CPU 119 is connected to the D1 terminal.
When the “L” level signal is input and the setting switch 131 is turned on, the “L” level signal is input to the D2 terminal of the lens barrel CPU 119. On the other hand, when the setting switch 132 is in the OFF operation, the D1 terminal of the lens barrel CPU 119 is at the “H” level, and when the setting switch 131 is in the OFF operation, the D2 terminal of the lens barrel CPU 119 is in the “H” level. Level.

When the D1 terminal is at the "L" level and the D2 terminal is at the "H" level, the shake correction control mode is
"Mode for performing correction operation only during exposure" is selected. D
When one terminal is at the “H” level and the D2 terminal is at the “L” level, the blur correction control mode is selected to “a mode in which a correction operation is performed during and after exposure”. When the D1 terminal is at the “H” level and the D2 terminal is at the “H” level, the blur correction control mode is selected to “the mode in which the blur correction operation is not performed”.

The shake detecting units 113 and 114 perform an analog process on an output signal corresponding to the detected shake amount, and input the signal to the lens barrel side CPU 119. When the blur correction control mode is selected in the “mode in which the correction operation is performed during and after exposure” and the half-push switch 111 is turned ON, the lens barrel side CPU 119
Calculates the amount of drive of the blur correction lens 127 based on the analog processed data. Shake detector 113, 1
14 outputs an output signal corresponding to the detected shake amount from the time when the power is applied.
9 starts the omega-zero detection process from the time when the output signals of the shake detection units 113 and 114 are output. The time required for detection of omega zero is about 2 seconds when the detection time is sufficient, but cannot be secured for 2 seconds at the time of photographing immediately after the power is turned on. In such a case, the detection of omega zero is performed over as long a time as possible. When the photographer performs photographing, the lens barrel side CPU 119 calculates a correction amount based on the detection data of omega zero until immediately before photographing, and performs feedback control of the motors 123 and 124 based on the correction amount.

The lens barrel-side CPU 119 instructs the control circuits 121 and 122 to drive the motors 123 and 124 based on the calculated correction amount. Rotational movements of the motors 123 and 124 are converted to linear movements,
7 is driven. Note that when the blur correction control mode is selected as the “mode in which the correction operation is performed only during exposure” and the full-press switch 110 is turned on,
The blur correction lens 127 is driven only during exposure.

FIG. 7 is a circuit diagram showing an example of a shake detection circuit in a conventional shake correction device. The shake detection circuit shown in FIG. 7 includes capacitors C11, C12, C1 in the first stage.
3, resistors R11, R12, R13 and operational amplifier OP1
And a third-order LPF (direct-current coupling) 10 consisting of a first CPF and a first-order HPF consisting of a capacitor C21 and a resistor R21 in the second stage.
(AC coupling) 20 and a 100-fold amplifier 30 including a capacitor C31, a resistor R31, and an operational amplifier OP31 at the third stage.

In FIG. 7, the input angular velocity signal is
Although the high-frequency component is cut off in the first-stage LPF 10, the phase of the signal in the pass band is simultaneously delayed. It is desirable that the phase delay be close to zero, in order to cause an error in the shake correction control. For this, L
The cutoff frequency of the PF 10 is set to such an extent that this phase delay can be ignored, for example, about 300 Hz. The waveform from which the high frequency component has been cut off is input to the second stage HPF 20.

FIG. 8 is a block diagram showing another example of a shake detection circuit in a conventional shake correction apparatus. An output signal corresponding to the amount of shake output from the angular velocity sensor 201 originally includes a low-frequency signal (a drift component over a long period of time), and the minimum detected amplitude is also small. As shown in FIG. 8, if the output signal output from the angular velocity sensor 201 is directly multiplied by the gain in the amplifier 204, the component of the output signal from the amplifier 204 is saturated by the low-frequency component and cannot be used. It will be something. In order to cut off low frequency components, as shown in FIG. 7, for example, an HP having a cutoff frequency of about 0.06 Hz is used.
F20 is used. As described above, in the circuit configuration shown in FIG. 7, the signal from which the low-frequency component and the high-frequency component are cut off is amplified by the third-stage amplifier 30, and this amplifier 30 constitutes a non-inverting amplifier circuit. And 10
The gain is multiplied by one. When the output signal output from the angular velocity sensor 201 is processed by the circuit configuration shown in FIG. 7, when an excessive input signal is applied to the amplifier 30, a signal multiplied by the gain of the amplifier 30 is output from the amplifier 30. Would.

FIG. 9 is a diagram schematically showing a state where the output voltage of the angular velocity sensor exceeds the dynamic range.
Since the dynamic range of the output voltage according to the amount of shake output from the angular velocity sensor 201 is limited by the power supply voltage and the circuit configuration of the output stage, the output voltage from the amplifier 30 is saturated as shown in FIG. Would. If left in this state, the output voltage will be HPF (AC coupled) 20
Due to the characteristics of (1), the reference point is infinitely approached due to the time constant of the circuit. However, since the time constant of the HPF 20 is on the order of several seconds, it takes a considerable time for the output voltage from the amplifier 30 to reach the reference point. Can not be performed. In order to avoid this, in the blur detection circuit shown in FIG. 7, the time constant of the HPF 20 is shortened by the analog switch SW41.

FIG. 10 is a diagram schematically showing a state in which the output voltage of the angular velocity sensor has been pulled back within the dynamic range. When the analog switch SW41 is turned on when the output voltage output from the angular velocity sensor 201 is saturated, as shown in FIG. 10, the output voltage from the amplifier 30 can be pulled back to the reference point in about 20 ms. it can.

FIG. 11 is a circuit diagram showing another example of a blur detection circuit in a conventional blur correction device. The shake detection circuit shown in FIG. 11 includes a capacitor C61 and a resistor R6 in the first stage.
1 and an operational amplifier OP61, an inverting amplifier 60 which also serves as an LPF and is DC cut, and a capacitor C in the second stage.
71, resistors R71, R72, R73 and operational amplifier OP
An inverting amplifier 70 also serving as an LPF 71, a capacitor C51 and a resistor R51, and an HPF 50 for cutting a direct current are provided.

In the shake detecting circuit shown in FIG. 11, offset adjustment is not required because the resistor connection portion to which the input gain of the operational amplifier OP61 is applied is DC-insulated by the capacitor C51. According to this circuit configuration, the gain of the first-stage inverting amplifier 60 is controlled by the first-stage operational amplifier OP6.
It does not work for an offset of 1. When the gain of the first stage is sufficiently increased and the gain of the next stage is decreased, the offset voltage appearing in the output naturally decreases. HPF5
The time constant of 0 is determined by the resistor R51 and the capacitor C51, and the resistor R51 has a function of setting a gain together with the resistor R61.

[0026]

In the conventional shake detecting circuit shown in FIG. 7, if the final stage of the operational amplifier OP31 between the HPF 20 and the amplifier 30 is affected by the input offset voltage, the offset voltage is changed to the operational amplifier OP31.
Is multiplied by the gain and output. When the input bias current affects the operational amplifier OP31 in the final stage, the balance between the bias currents of the “+” terminal and the “−” terminal of the operational amplifier OP31 depends on whether the analog switch SW41 is on or off. Changes. This change in the balance of the bias current results in a change in the voltage, which appears as an output from the operational amplifier OP31. In order to prevent these output saturations, the blur detection circuit shown in FIG. 7 performs offset adjustment using the variable resistor R44, but this offset adjustment cannot be ignored in terms of cost.

In the conventional shake detecting circuit shown in FIG. 11, when it is desired to reduce the gain of the second-stage inverting amplifier 70 related to the offset, the first-stage inverting amplifier 60 is used.
It is necessary to gain a gain in. As a result, HPF5
The capacitance of the capacitor C51 for which a time constant of 0 has been set is dependently increased. When the capacity of the capacitor C51 increases, the analog switch S
The convergence time when the W61 and SW81 are turned on becomes long.

FIG. 12 is a table showing the voltage when the difference voltage from the steady state at the elapsed time t is multiplied by the gain (100) when the step voltage of E = 5 V is input to the HPF 50 at time 0. is there. For example, in order to keep the amplifier output fluctuation voltage at 168 mV (1.68 deg / sec) or less, the time during which the analog switch SW81 is turned on is as follows.
A maximum of 340 ms is required.

An object of the present invention is, first, when a vibration detection signal is processed by a processing circuit, an offset component multiplied by a gain and output in a final stage of the processing circuit is expressed by:
An object of the present invention is to provide a blur correction device that can be reduced without performing offset adjustment. Second, it is an object of the present invention to provide a blur correction device capable of quickly converging the output voltage to an amplification reference voltage before the output voltage is saturated.

[0030]

The present invention solves the above-mentioned problems by the following means. In addition, in order to make it easy to understand, description is given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this. That is, the first aspect of the present invention provides a photographing optical system (125, 12
6, 127) in a direction perpendicular to the optical axis to correct blur, and a drive unit (123, 124) for driving the blur correction optical system. And a shake detecting section (113, 114) for detecting a shake and outputting an output voltage corresponding to the shake amount.
And a control unit (119, 12) for driving and controlling the driving unit.
1, 122), a DC voltage generating section (90) for generating a DC voltage, and a predetermined operation based on the output voltage of the blur detecting section and the DC voltage to generate an output signal. The control unit performs the operation when the output signal is not within a predetermined range.
An operation signal generator (2a) for generating an operation signal (SSW)
The DC voltage generator generates a DC voltage based on the operation signal, and the calculator sets an output signal within a predetermined range based on an output voltage of the blur detector and the DC voltage. It is characterized by the following.

According to a second aspect of the present invention, in the shake correction apparatus according to the first aspect, the predetermined range is a range that does not exceed a dynamic range.

[0032] The invention of claim 3 is the invention of claim 1 or claim 2.
Wherein the shake detection unit, the calculation unit, and the control unit are DC-coupled (40).

[0033] The invention of claim 4 is the invention of claims 1 to 3.
In the image stabilization device according to any one of the above, the DC voltage generation unit includes a DC voltage value variable unit (SW91) that varies a DC voltage value based on the operation signal.

According to a fifth aspect of the present invention, in the shake correction apparatus according to the fourth aspect, the control unit includes a pulse width modulation unit (2a) for generating an operation signal, and the DC voltage value variable unit includes the pulse width modulation unit. A switch section (SW9) operated by an operation signal
1) is provided.

According to a sixth aspect of the present invention, there is provided the first to third aspects.
In the image stabilization device according to any one of the above, the control unit includes a pulse width modulation unit (2) that generates an operation signal.
a) wherein the DC voltage generator operates based on the operation signal and switches an output voltage of a DC voltage source; and a low-pass filter (403) which smoothes the switched rectangular wave. ).

[0036] The invention of claim 7 is the invention of claims 4 to 6.
In the blur correction device according to any one of the above, the operation signal generation unit generates the operation signal before the output signal exceeds the dynamic range, and the DC voltage value variable unit, the switching unit, or The switch unit varies a DC voltage value according to a ratio (DUTY) between an ON operation time and an OFF operation time of the operation signal.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, an embodiment of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a block diagram showing a shake detection circuit in the shake correction device according to the first embodiment of the present invention. As shown in FIG. 1, a shake detection circuit according to the first embodiment of the present invention detects an shake and outputs an output signal (output voltage) corresponding to the amount of shake, and is connected to the angular speed sensor 1. L that cuts off high frequency components from the output signal of the angular velocity sensor 1
The LPF 3 is connected to the PF 302 and the LPF 302.
02, an amplifier 304 for amplifying the output signal of the
4 and a CPU 2 having a built-in A / D converter 2a to which the output signal of the amplifier 304 is input. Pulse width modulation control unit (Pulse Width Modulation) built in CPU 2
A DC voltage output unit 303 is connected to (hereinafter, referred to as a PWM control unit) 2b. The DC voltage output unit 303
The amplifier 304 outputs a DC voltage so as to provide a negative feedback with respect to the input of the amplifier 304, and the amplifier 304 adds (subtracts by a sign) the output voltage of the angular velocity sensor 1 and amplifies it. The lens barrel side CPU 119 controls the driving of the motors 123 and 124 based on the DC voltage amplified by the amplifier 304 and the output voltage of the angular velocity sensor 1.
21 and 122, and the blur correction lens 127 is driven by the motors 123 and 124 to correct blur. In this shake detection circuit, the range from the input to the output is DC-coupled, and the amplified signal voltage depends on the output voltage.

FIG. 2 is a circuit diagram showing a shake detection circuit in the shake detection device according to the first embodiment. The shake detection circuit shown in FIG. 2 detects an shake, outputs an output voltage corresponding to the shake amount, and resistors R41 and R41.
42, capacitors C41 and C42 and operational amplifier OP4
1 and an inductor H
An LPF is composed of a constant voltage DC power supply E91, a switch SW91, and a diode D9.
1, a DC voltage output circuit 90 including resistors R1 and R8,
3 to form an adder, and resistors R81, R8
3, an addition amplifier circuit 80 constituting an amplifier with the R84 and the operational amplifier OP81, and an A / D converter 2a to which an output voltage of the addition amplifier circuit 80 is input, and a CPU 2 having a built-in PMW unit 2b for generating an operation signal SSW.

Specific examples of actual constant setting in the shake detection circuit shown in FIG. 2 are R41: 47 kΩ, R42: 47 k
Ω, R81: 4.7 kΩ, R82: 9.1 kΩ, R8
3: 470 kΩ, R84: 3.0 kΩ, C41: 0.0
1 μF, C42: 4700 pF.

Next, the operation of the blur detection circuit in the blur correction device according to the first embodiment of the present invention will be described. The output voltage corresponding to the amount of shake detected by the angular velocity sensor 1 is
The high-frequency component is cut off by the LPF 40 in the next stage, and only the signal in the predetermined band is
Gain. The output voltage of the addition amplification circuit 80 is input to the A / D converter 2a of the CPU 2. When an excessive shake is input to the angular velocity sensor 1, the output voltage of the addition amplification circuit 80 may not be within the dynamic range. For example, when a shake having an output waveform as shown in FIG. 9 is input to the angular velocity sensor 1, this output waveform is equivalent to the angular velocity ± 15 which is the dynamic range of the circuit.
deg / sec. In this state,
The output of the circuit is not normal, and after the output waveform is saturated, the circuit is in a non-functional state. As shown in FIG. 9, when the angular velocity sensor 1 outputs an excessive signal in the + direction, the output voltage of the operational amplifier OP41, which is the output stage of the LPF 40, has a gain of 0 dB.
An operational amplifier OP8 which is the next inverting amplification stage with the same polarity.
Enter 1 Operational amplifier OP to which excessive voltage is input
81 attempts to supply current to the imaginary short point A.

The CPU 2 monitors the A / D value of the output voltage of the addition amplification circuit 80 input to the A / D converter 2a, and compares the monitored value with a predetermined value. At the moment when the magnitude of the monitor value and the predetermined value are switched, the CPU 2 determines that the output voltage of the addition amplification circuit 80 may exceed the dynamic range, and determines that the generation of the operation signal SSW is PW.
It instructs the M control unit 2b. The switch SW91 performs an ON operation and an OFF operation based on the operation signal SSW,
The output voltage of the constant voltage DC power supply E91 depends on this ON operation and O
It is converted into a rectangular wave by the FF operation. This square wave
The effective voltage value is determined by the ratio between the ON time and the OFF time of the switch SW91 (hereinafter referred to as DUTY). The LPF of the next stage including the inductor H91 and the capacitor C91 converts this rectangular wave into a smooth DC voltage. The switch SW91 is ON for the diode D91.
At the moment when the operation is changed from the operation to the OFF operation, the inductor H91
The purpose of this is to provide a path for the energy stored as a current in the device.

The CPU 2 changes DYTY of the PWM control section 2b to a predetermined value at the moment when the magnitude of the monitor value and the predetermined value are switched. As a result, the switch SW91 is set to O
The effective area per one cycle of the rectangular wave during the N operations is changed, and the DC output voltage value can be varied.
The DC voltage output from the DC voltage output circuit 90 is controlled by the gain determined by the resistors R82 and R83 so that the DC voltage output from the DC voltage output circuit 90 is substantially equal to that obtained by applying negative feedback.
It is added to the output voltage from the PF 40 (subtracted by the sign). As a result, the current flowing into the imaginary short point A is absorbed by the DC voltage output circuit 90 connected to the resistor R82. As a result, the output voltage of the operational amplifier circuit 80 is level-shifted before being saturated beyond the dynamic range, and the output voltage of the angular velocity sensor 1 is amplified at or near the reference voltage Vref of the angular velocity sensor 1. Note that when the DC output voltage value output from the DC voltage output circuit 90 is lower than the reference voltage Vref, the current trying to flow into the imaginary short point A can be absorbed by the DC output voltage value. The DC output voltage value can be reduced by shortening the ON operation time (DUTY ratio) of the switch SW91.

In the first embodiment of the present invention, as in the conventional shake detecting circuit shown in FIG.
1, the DC voltage output circuit 90
, The level of the output voltage of the operational amplifier circuit 80 can be shifted. In the first embodiment of the present invention, a DC voltage corresponding to the final output value of the amplifier 304 is added to the amplification input stage of the amplifier 304 that processes the output voltage of the angular velocity sensor 1. For this reason, in the first embodiment of the present invention, it is possible to configure a circuit that does not need to adjust the input offset component of the operational amplifier. Further, an inexpensive component having a large offset can be used for the operational amplifier that amplifies the output voltage of the angular velocity sensor 1, and the amplification function can be realized without adjusting the input offset component.

In the first embodiment of the present invention, when an excessive shake is input to the angular velocity sensor 1, the voltage to be added is changed just before the output voltage is overranged, and the output voltage is quickly changed to the vicinity of the reference voltage. Can converge. Further, in the first embodiment of the present invention, by adjusting the DC added voltage value before the output voltage is saturated, it is possible to always capture a signal within the dynamic range. In the first embodiment of the present invention, the DC voltage to be added can be changed by changing the DUTY of the ON operation and the OFF operation of the switch SW91. Therefore, it is not necessary to use an expensive D / A converter or the like to generate the DC added voltage value, and a low-cost circuit advantageous in cost can be configured.

(Second Embodiment) Hereinafter, referring to the drawings,
A second embodiment of the present invention will be described. In the following description, circuit portions that are the same as the circuit portions described in the first embodiment of the present invention are denoted by the same reference numerals, and a detailed description thereof will be omitted. FIG.
FIG. 6 is a block diagram illustrating a shake detection circuit in a shake correction device according to a second embodiment of the present invention. Second embodiment of the present invention
In the shake detection circuit according to the embodiment, after the output signal (output voltage) of the angular velocity sensor 1 is amplified by the amplifier 304, the high frequency component is cut off by the LPF 302,
It is input to the A / D converter 2a built in U2.
In the second embodiment of the present invention, when there is a possibility that the output voltage does not fall within the dynamic range, the amplifier 304 adds (subtracts by sign) the output voltage of the DC voltage output unit 303 and the output voltage of the angular velocity sensor 1. And amplify. The LPF 302 removes high frequency components from the amplified output signal.

In the second embodiment of the present invention, the amplifier 304
Since the LPF 302 is provided at the next stage, the noise component of the operational amplifier constituting the amplifier 304 can also be removed by the LPF 302.

(Third Embodiment) Hereinafter, referring to the drawings,
A third embodiment of the present invention will be described. FIG. 4 is a block diagram showing a DC voltage output unit of a shake detection circuit in a shake correction device according to a third embodiment of the present invention. A DC voltage output unit 400 according to the third embodiment of the present invention includes a DC voltage source 401, a switching unit 402 that performs switching operation of an output signal (output voltage) of the DC voltage source 401 by a PWM control unit 404, and a switching unit 402. An LPF 403 outputs a smoothed DC voltage by blocking high-frequency components from the rectangular wave converted by 402.

(Other Embodiments) The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the equivalent scope of the present invention. For example, P
When the WM control unit 2b is not provided in the CPU, PW
The IC of the M control unit 2b may be externally connected to the CPU and controlled by the CPU. Also, the shake detection units 113 and 11
4 is not limited to an angular velocity sensor, but the present invention is also effective for an acceleration sensor and other sensors. For example, when using an angular acceleration sensor, the angular acceleration signal is first integrated and converted into an angular velocity signal. Furthermore, in the embodiment of the present invention, the example in which the blur correction device is mounted on the still camera has been described.

[0049]

As described above in detail, according to the first aspect of the present invention, when the output signal of the arithmetic unit is not within the predetermined range, the control unit causes the DC voltage generation unit to generate a DC voltage, The calculation unit performs a predetermined calculation based on the DC voltage and the output voltage of the shake detection unit, and sets the output voltage of the shake detection unit within a predetermined range. Therefore, the offset component can be reduced without performing offset adjustment. With
It is possible to quickly converge the output voltage of the blur detection unit to the vicinity of the reference voltage.

According to the second aspect of the present invention, the predetermined range is a range that does not exceed the dynamic range. Therefore, when an excessive shake is input to the shake detecting unit, the dynamic range is set before the output voltage exceeds the range. The signal can be captured within the range, and the output signal can quickly converge to the vicinity of the reference voltage.

According to the third aspect of the present invention, since the shake detecting section, the calculating section and the control section are DC-coupled, the vibration detecting signal included in the low frequency component can be effectively used.

According to the fourth aspect of the present invention, since the DC voltage generating section includes the DC voltage value changing section for changing the DC voltage value, the DC voltage and the vibration detection signal changed to an arbitrary voltage value are provided. , The output signal can be within a predetermined range.

According to the fifth aspect of the present invention, the control unit includes:
It has a pulse width modulation section that generates an operation signal, and the DC voltage value variable section has a switch section that operates according to the operation signal.
The DC voltage generated by the DC voltage generator can be changed to an arbitrary voltage value.

According to the sixth aspect of the present invention, the DC voltage generator operates based on the operation signal and switches the output voltage of the DC voltage source, and the low-pass smoothes the switched rectangular wave. Since the filter is provided, the DC voltage generated by the DC voltage generator can be determined as an effective voltage value, and can be converted into a smoothed DC voltage.

According to the seventh aspect of the present invention, the DC voltage value changing section, the switching section or the switch section changes the DC voltage value according to the ratio between the ON operation time and the OFF operation time of the operation signal. The effective voltage value of the DC voltage generated by the generator can be determined to an arbitrary voltage value.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a shake detection circuit of a shake correction device according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a shake detection circuit of the shake correction device according to the first embodiment of the present invention.

FIG. 3 is a block diagram illustrating a shake detection circuit of a shake correction device according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a DC voltage output unit in a shake detection circuit of a shake correction device according to a third embodiment of the present invention.

FIG. 5 is a block diagram of a conventional shake correction device.

FIG. 6 is a block diagram illustrating an example of a shake detection circuit of a conventional shake correction device.

FIG. 7 is a circuit diagram illustrating an example of a shake detection circuit of a conventional shake correction device.

FIG. 8 is a block diagram showing another example of the shake detection circuit of the conventional shake correction device.

FIG. 9 is a diagram schematically showing a state in which the output voltage of the angular velocity sensor exceeds a dynamic range.

FIG. 10 is a diagram schematically showing a state in which the output voltage of the angular velocity sensor has been pulled back within the dynamic range.

FIG. 11 is a circuit diagram showing another example of a shake detection circuit of a conventional shake correction device.

FIG. 12 is a table showing a voltage when a step voltage of E = 5V is input to the HPF at time 0 and a voltage (difference from a steady state at an elapsed time t) is multiplied by a gain (100).

[Explanation of symbols]

 Reference Signs List 1 angular velocity sensor 2 CPU 2a A / D converter 2b PWM control unit 40 LPF 80 addition amplifier 90 DC voltage output circuit 113,114 blur detection unit 121,122 control circuit 123,124 motor 127 blur correction lens 201 angular speed sensor 202 LPF 203 HPF 204 Amplifier 205 A / D converter 302 LPF 303 DC voltage output unit 304 Amplifier 400 DC voltage output circuit 402 Switching unit 403 LPF SSW Operation signal SW91 Switch

Claims (7)

[Claims] 1. A blur correction optical system that corrects a blur by driving at least a part of a photographing optical system in a direction perpendicular to an optical axis; a driving unit that drives the blur correction optical system; A shake detection unit that outputs an output voltage according to the shake amount; and a control unit that drives and controls the drive unit. An operation unit that performs a predetermined operation based on an output voltage of the unit and the DC voltage to generate an output signal, wherein the control unit generates an operation signal when the output signal is not within a predetermined range. A signal generation unit, wherein the DC voltage generation unit generates a DC voltage based on the operation signal, and the calculation unit sets an output signal in a predetermined range based on the output voltage of the blur detection unit and the DC voltage. Inside An image stabilization device, characterized in that: 2. The blur correction device according to claim 1, wherein the predetermined range is a range that does not exceed a dynamic range. 3. The blur correction device according to claim 1, wherein the blur detection unit, the calculation unit, and the control unit are DC-coupled. 4. One of claims 1 to 3
The blur correction device according to claim 1, wherein the DC voltage generation unit includes a DC voltage value variable unit that changes a DC voltage value based on the operation signal. 5. The blur correction device according to claim 4, wherein the control unit includes a pulse width modulation unit that generates an operation signal, and the DC voltage value variable unit includes a switch unit that operates according to the operation signal. An image stabilization device comprising: 6. Any one of claims 1 to 3
In the blur correction device according to the item, the control unit includes a pulse width modulation unit that generates an operation signal, the DC voltage generation unit operates based on the operation signal, and switches an output voltage of a DC voltage source. And a low-pass filter for smoothing the switched rectangular wave. 7. Any one of claims 4 to 6
In the blur correction device according to the item, the operation signal generation unit generates the operation signal before the output signal exceeds the dynamic range, the DC voltage value variable unit, the switching unit or the switch unit, A blur correction device, wherein a DC voltage value is varied according to a ratio between an ON operation time and an OFF operation time of the operation signal.